Last week’s attacks have heightened concerns Thailand’s long-running but local southern Islamist insurgency may have spread after years of stalled peace talks -- a suggestion the kingdom’s junta has been keen to deny.

A string of overnight attacks have highlighted how the insurgency continues to rage in the three Muslim majority provinces bordering Malaysia.

“One soldier was seriously injured from a bomb buried under the road” on Monday morning, Police captain Wiroge Boonkae, from Bacho police station in southern Narathiwat province, told AFP.

Police said a further three blasts struck neighbouring Yala province, though no injuries were reported.

The area, which was annexed a century ago by Thailand, has been battered by 12 years of violence between the Buddhist-majority state and shadowy Muslim rebels seeking greater autonomy.

Near-daily shootings and roadside bombs have left more than 6,500 dead since 2004, most of them civilians.

But the violence has largely remained local with militants loathe to spark international outrage by targeting Western tourists.

Last week’s attacks hit tourist resort towns further north -- a highly unusual assault in a country where foreign visitors are rarely caught up in political violence.

The attacks bore many hallmarks of the southern insurgents, who never claim their operations, including coordinated multiple strikes and the type of devices used.

Four people died and scores were wounded, including many European tourists.

No one has claimed responsibility for the bombing spree but Thai authorities have ruled out international terrorism and say the culprits are “local saboteurs”.

But they have dismissed any suggestion southern insurgents were behind the attacks.

“It is not right to say it is an extension of the deep south insurgency,” deputy junta chief General Prawit Wongsuwan told reporters on Monday.

Thai soldiers watch as a forensic unit inspects the scene of an attack following two roadside bomb blasts at four separate locations by suspected separatist militants in the Bacho district of Thailand.
(AFP Photo)

With southern insurgents ruled out by the junta, official suspicion has fallen on militants within the so-called “Red Shirt” movement loyal to ousted premier Thaksin Shinawatra.

The Red Shirts have denied any suggestion of involvement and accused the junta of using the bomb blasts to roll out a fresh crackdown against them.

Analysts have been cautious about the capability of militant Red Shirts to carry out such a sophisticated attack.

Away from the deep south, Thailand has been battered by a decade of political unrest, driven by a bitter power struggle between the military-allied elite and populist forces loyal to ousted democratically-elected governments run by the Shinawatra clan.

The blasts are seen as an affront to a military government that prides itself on having brought some stability to Thailand since its 2014 coup.

The bombings in top tourist destinations threaten a vital source of income for tropical Thailand.

The sector accounts for at least 10% of an economy the military government has struggled to revive.